About 322 genera and 8910 species: widespread throughout the world, primarily in the tropics and subtropics, more poorly represented in temperate regions; 75 genera (one endemic, nine introduced) and 406 species (99 endemic, 27 introduced) in China, nearly 95% of which are found in the S and SW parts of the country.

Fifty-nine genera and over 1700 species: mostly tropical, the greatest diversity in SE Asia; 16 genera and 138 species (41 endemic, four introduced) in China.

Four genera and ca. 210 species: throughout the tropics; two genera and 13 species (three endemic) in China.

Two hundred and eighteen genera and over 5700 species: widespread throughout the world, primarily in the tropics and subtropics, more poorly represented in temperate regions; 54 genera (one endemic, nine introduced) and 255 species (55 endemic, 23 introduced) in China.

The Euphorbiaceae as treated here include the following families that have been proposed for segregation: Androstachydaceae, Antidesmataceae, Bischofiaceae, Hymenocardiaceae, Phyllanthaceae, Pedilanthaceae, Picrodendraceae, Porantheraceae, Putranjivaceae, Ricinocarpaceae, Scepaceae, Stilaginaceae, Trewiaceae, and Uapacaceae. The Pandaceae and Buxaceae, formerly included here, are now well established as separate families.

Molecular data has shown that the traditional concept of Euphorbiaceae includes three major lineages that are relatively distantly related to each other: the Phyllanthoids (genera 1-16 in this account), the Putranjivoids (genera 17 and 18), and the Euphorbioids (genera 19-75).

Many species of Euphorbiaceae are of economic importance, probably most importantly as the main source of rubber (Hevea) but also as sources of medicine; foods, both as a staple starch source (Manihot) and fruits (e.g., Phyllanthus emblica); seed oils (Ricinus, Vernicia); and insecticides.

The Putranjivoid genera resemble phyllanthoids by their 2-ranked leaves, frequently rather small fasciculate flowers, and ovules 2 per locule. They can be distinguished by their leaf blades, stigmas, and fruit. Also, the leaves contain mustard oils and so frequently taste peppery when fresh, although the taste may take a little time to develop.